The invention relates to the use of the substance known under the name of galiella lactone as pharmaceutical, in particular for the treatment of inflammatory processes.
Inflammations are distinguished by a large number of changes even in organ systems which are not in the immediate vicinity of the site of the inflammation. All the systemic changes associated with an inflammation are embraced by the term xe2x80x9cacute phase responsexe2x80x9d. This also applies to chronic inflammatory phenomena (Perspect. Biol. Med., 1993, 36: 611-22). The principal part is played in the development of acute phase response by the altered rate of synthesis of so-called acute phase proteins (AP proteins) in the liver (N. Engl. J. Med., 1999, 340: 448-54). The acute phase response occurs in infections, traumats, operations, burns, organ damage and advanced stages of malignant diseases. The main mediator of the acute phase response is interleukin-6 (IL-6) (Proc. Natl. Acad. Sci. USA, 1987, 84: 7251-5).
IL-6 uses tyrosine kinases from the Janus Kinase (Jak) family and transcription factors from the signal transducer and acovator of transcription (Stat) family as the main mediators of intracellular signal transduction. IL-6 induces phosphorylation and thus activation of the transcription factors Stat3 and Stat1 (to a smaller extent) (Science, 1994, 264: 1415-21: Science, 1997, 277: 1630-5). After the activation. Stat3 and Stat1 are translocated into the cell nucleus and, after binding to their binding sites on the DNA, cause expression of the genes of AP proteins therein (Biochem. J., 1998, 334: 297-314).
Treatments of inflammatory processes corresponding to the current state of the art, for example with corticosteriods, are not without unwanted side effects. There is a need for therapeutic agents which reduce or suppress the unwanted or unwantedly strong expression of the IL-6 -induced AP proteins in the diseases mentioned above and below without at the same time intervening elsewhere in cellular metabolism. For this reason, Stat3 is regarded as a suitable target for developing novel active substances against a non-beneficial, excessive (not self-limiting) acute phase response as is present, for example, in the case of cirrhosis of the liver.
It has now been found, surprisingly, that the compound of the formula (I). 
which is called galiella lactone is outstandingly suitable for the treatment of inflammatory processes induced by excessive expression of the IL-6-induced acute phase proteins. In this connection, the substance has a specific effect on IL-6 signal induction which has not previously been disclosed for any substance.
Galiella lactone of the formula (I) is disclosed in Z. Naturforsch. 1990, 45 c; 1093-8 (and the thesis by R. Hautzel, University of Kaiserslautem 1989) and can be isolated from the fungus Galiella rufa (subdivision Ascomycotina, class Discomycotina, order Pezizales, family Sarcosomaraceae, genus Galiella) as described therein or in the thesis by H. J. Knerr, University of Kaiserslaurem 1995. No report of its use as pharmaceutical has appeared to date. Galiella rufa is described, for example, in: Gary H. Lincoff, Carol Nehring, The Audubon Society Field Guide to North American Mushrooms, Alfred A. Knopf, N.Y. 1981.
Galiella lactone has the physical and chemical properties described hereinafter. Galiella lactone forms white crystals which are readily soluble in polar solvents (methanol, pyridine, ethyl acetaze, acetonitrile, tert-butyl methyl ether (lMBE), tetrahydrofurn (THF) and water) and scarcely soluble in nonpolar solvents (cyclohexane, n-pentane, n-hexane). It was possible with the aid of the mass spectra (Table 1) to establish firstly the molecular weight of 194 Da and then the molecular formula of C11H14O3.
The structure was elucidated by means of two-dimensional homonuclear and heteronuclear NMR spectroscopy (1H and 13C). The assignment of the NMR signals to the respective nuclei can be found in Table 2. The UV spectrum of galiella lactone shows a maximum at 219 nm. The characteristic peaks in the IR spectrum and their assignment can be found in Table 3.
The invention also relates to pharmacologically active derivatives of galiella lactone and their use analogous to galiella lactone. 
In the 1930s, the inflammatory phenomena leading to changes in organ systems were investigated in detail for the first time. This led to the discovery of C-reactive protein (so-called because it reacts with the C polysaccharide of pneumococci) in the plasma of patients during the acute phase of pneumonia induced by pneumococci. Since then, all systemic changes associated with an inflammation are summarized by the term xe2x80x9cacute phase responsexe2x80x9d, and this also applies to chronic inflammatory phenomena.
A rather arbitrary distinction is made between two aspects of the acute phase response: thus, on the one hand, changes in concentration of many proteins in the plasma, the so-called acute phase proteins (AP proteins), are observed (Table 4) and, on the other hand, changes occur in the behaviour and general physiological state (see Table 5). The latter are, of course, caused by the former. A protein is included by definition in the group of AP proteins if, during inflammatory disorders, its plasma concentration increases (positive AP proteins) or decreases (negative AP proteins) by at least 25% (ef., for example, Ann. N.Y. Acad. Sci. 1982, 389: 406-18). The changes in concentrations of the AP proteins derive principally from their altered rate of synthesis in the liver.
The level of induction of the individual proteins varies widely. Thus, the plasma level of ceruloplasmin increases by just 50%, whereas that of C-reactive protein increases by a factor of 1000.
Signal transducer and activator of transcription 3 (Stat3) assumes a special role in the control of the expression of genes having in their promoter sequence an IL-6 responsive element of class II (IL-6RE IL, synonymous with acute phase responsive element, APRE) (5xe2x80x2-TTNNNNAA-3xe2x80x2 or 5xe2x80x2-TTNNNNNAA-3xe2x80x2). To this extent, Stat3 is a transcription factor. However, the physiological activity of Stat3in the control of gene expression is subject to the following principle of regulation:
binding of IL-6 to a receptor complex consisting of the IL-6 receptor and two gp130 molecules results in activation of the gp130-associated kinases Jak1, Jak2 and Tyk2. These initially phosphorylate tyrosine residues in the cytoplasmic part of gp130, which thus become binding sites for SH2 domains of Stat1 and Stat3. After the Stats have bound, they are phosphorylated by the Jaks at specific tyrosine residues and subsequently form homodimers or heterodimers. The activated dimers are translocated into the core, bind to IL-6RE II there are subsequently induce the transcription of the targets genes. On their way into the cell nucleus or in the cell nucleus, the dimers are also phosphorylated on specific serine residues by an as yet unknown serine kinase (Biochem. J., 1998, 334: 297-314).
A crucial feature of Stat3 compared with other transcription factors is that Stat3 is a primary transcription factor. Primary transcription factors are already present in the cell in inactive form and are activated by an appropriate stimulus in order to be able to display their effect very rapidly. Primary transcription factors are not formed only on activation of the relevant gene and subsequent transcription and translation.
Since the abovementioned gp130-associated kinases Jak1, Jak2 and Tyk2 are also involved in other intracellular signal transduction pathways which, because of the unwanted effects resulting therefrom, are not to be inhibited, they do not represent suitable targets for selective inhibition of the Stat3-mediated gene expression. By contrast, a chemical compound which selectively prevents the binding of Stat3 to its DNA binding sites (IL-6RE II, see above) ought to be useful as pharmaceutical for suppressing Stat3- and thus also IL-6-mediated disease processes.
Stat3 is able primarily to promote all pathophysiological processes involving genes having the Stat3 binding sequence (IL-6RE II) in their promoter. These are specifically genes which play a crucial causative part in immunological complications, in inflammatory diseases, septic shock degenerative diseases such as secondary amyloidosis or else chronic inflammatory diseases such as cirrhosis of the liver. Tab. 5 summarizes the changes occurring when Stat3 activity is increased.
The acute phase response occurs in association with infections, traumata, operations, burns, organ damage and advanced stages of malignant diseases.
The main mediator of the acute phase response is interleukin-6 (IL-6). IL-6 additionally influences a large number of physiological processes. Examples which may be mentioned are bone metabolism, haematopoiesis, immune response, inflammatory processes, development of nerve cells, and cellular proliferation. However, the role of IL-6 in the development of cirrhosis of the liver is of crucial importance (Gastroenterology 1994, 107: 789-98). In patients with cirrhosis of the liver there is found to be a positive correlation between the IL-6 plasma level and the organ failure, and the increased secretion of IgA and IgG by peripheral monocytes (Gastroenterology 1992, 103: 1296-301: Jama 1995; 274: 58-65). It has additionally been possible to show the IL-6 induces the expression of fibrinogen in the liver (Science 1996, 274: 1379-83). It is assumed that these changes play a central part in the development of fibrous tissue in the diseased liver, which eventually leads to cirrhosis of the liver (Drug Discovery Today 1998, 3: 202-13).
The effect according to the invention of galiella lactone is based on the specific inhibition of IL-6 signal induction. Galiella lactone is therefore generally suitable for the prophylaxis and/or treatment of inflammatory processes and their sequelae.
Stat3 is likewise an essential factor in the regulation of cell growth, the survival of cells and in cell differentiation (Oncogene 2000, 19: 2548-2556) It was possible to show that, for example in rat tumours and human prostate tumours, Stat3 is constitutively activated and that this activation correlates with the malignant potential of the tumours (Cancer Research 2000, 60: 1225-1228). Inhibition of Stat3 inhibits the growth of prostate tumour cells significantly. These results show that activation of Stat3 is essential for the progression of prostate tumour cells and that inhibition thereof has a great therapeutic potential for treating prostate tumours.
The importance of the activation of Stat3 has also been described for other types of tumours, for example for the tumours summarized by the term head and neck cancer, for breast cancer and uterine cancer (International Journal of Oncology 2000, 17: 23-28), and melanomas (skin cancer), tumours on the ovary, gliomas (brain tumours) and lung tumours (Molecular Medicine Today 1999, 5: 406-412).
Besides its well-described function as mediator of the acute phase response, IL-6 has also been described as an important regulator of cellular functions in the nervous system. Several studies have shown that IL-6 is involved both in physiological and in pathophysiological processes within the central nervous system (CNS) (Molecular Neurobiology 1997, 15: 307-339).
In the adult CNS (parenchyma and cerebrospinal fluid), the IL-6 levels are low or are below the detection limit. Significantly increased IL-6 levels occur, however, as a common feature of CNS injuries, inflammations and diseases. Increased IL-6 levels have been found, for example, in brain homogenates or cerebrospinal fluid in animal models of multiple sclerosis (European Journal of Immunology 1990, 20: 233-235) and multiple sclerosis patients (Cytokine 1993, 5: 583-588), in animal models of Parkinsons""s disease (Clinical and Experimental Pharmacology and Physiology 1999, 26: 680-683) and Parkinson patients (Advances in Neurology 1999, 80: 135-139), in patients suffering from Alzheimer""s disease (Acta Neuropathologica 1995, 89: 544-551), in animal models of neuropathic pain (Molecular Brain Research 1998, 62: 228-235), and in various types of CNS infections (for example Clinical and Experimental Immunology 1998, 71: 320-323). The main sources of IL-6 under these conditions appear to be astrocytes, microglia, neurons and, in some cases, immigrating immune cells (American Journal of Physiology 1992, 263: C1-C16).
Relatively little is known about the effects of IL-6 within the CNS, although it has been assumed that it might have protective functions. This theory derives essentially from in vitro observations indicating a survival- and differentiation-promoting effect of IL-6 on various types of cells in CNS. Studies on transgenic animals with IL-6 expression in the CNS suggest, however, that dysregulation of IL-6 production contributes to the neutropathology and pathophysiology of many CNS disorders. Two different approaches have been taken for overexpression of IL-6 selectively in the CNS: expression of human IL-6 in CNS neurons under the control of the promoter for rat neuron-specific enolase (NSE-IL-6 mice) (European Journal of Neuroscience 1995, 7: 2442-2449) and expression of murine IL-6 in astrocytes under the control of the murine GFAP promoter (GFAP-IL6 mice) (Proceedings of the Natural Academy of Sciences, USA 1993, 90: 10061-10065). In the NSE-IL6 model, reactive gliosis was found throughout the brain, but this was not associated with a general pathology of neuronal cell populations, of the CNS vascular system or changes in behaviour. In contrast to this, severe neuronal and vascular pathologies, in addition to reactive gliotic processes, have been described in GFAP-IL6 mice. Thus, GFAP-IL-b 6 mice show distinct signs of neurodegeneration, inflammatory processes in the brain, disturbances of blood-brain barrier function and altered electroencephalographic activity. These changes are associated with marked learning deficits and a number of motor disturbances such as disturbed motor coordination, ataxia and tremor.
Galiella lactone is particularly suitable for the prophylaxis and treatment of
fibrotic disorders of the liver and other organs,
cerebrovascular disorders such as, for example, stroke, traumatic injuries to the brain or spinal cord and their sequelae,
autoimmune diseases affecting the CNS or PNS, such as, for example, multiple sclerosis, peripheral autoimmune neuropathies,
chronic neurodegenerative disorders such as, for example, Alzheimer""s disease, Parkinson""s disease,
psychological disorders such as, for example, depression, anxiety, psychoses,
peripheral neuropathies of varying cause such as, for example, diabetic neuropathy,
pain caused both central and peripheral pathophysiological mechanisms,
cardivascular disorders such as coronary heart disease, arteriosclerosis and restenosis,
inflammatory disorders of the gastrointestinal tract such as Crohn""s disease (regional enteritis),
amyloidoses such as rheumatoid arthritis and
Stat3-dependent tumours such as head and neck cancer, breast cancer, uterine cancer and prostate cancer and melanomas, ovarian tumours, gliomas, carcinomas of the lung, and cachexia-inducing tumours.
The present invention also includes pharmaceutical preparations which, besides inert, nontoxic, pharmaceutically suitable excipients and carrier, contain galiella lactone, or which consist of galiella lactone, and processes for producing these preparations.
Galiella lactone should be present in these preparation in a concentration of 0.1 to 99.5% by weight, preferably of 0.5 to 95% by weight, of the complete mixture.
Besides galiella lactone, the pharmaceutical preparations may also contain other pharmaceutical active substances.
The abovementioned pharmaceutical preparations can be produced in a conventional way by known methods, for example with the excipient(s) or carrier(s).
Galiella lactone should normally be administered in total amounts of about 0.01 to about 100 mg/kg, preferably in total amounts of about 1 mg/kg to 50 mg/kg, of body weight every 24 hours, where appropriate in the form of several individual doses, to achieve the desired result.
However, it may be advantageous where appropriate to deviate from the stated amounts, specifically depending on the nature and body weight of the subject treated, on the individual behaviour toward the medicament, on the nature and severity of the disorder, the type of preparation and administration, and the time or interval over which administration takes place.
The effect is demonstrated by means of the following examples without any restriction being inferable therefrom.